Ignition System: Testing and Inspection

Misfire recognition, checking

Special tools and equipment
- VAG1551 Scan Tool or vehicle system tester VAG1552 with cable VAG1551/3

Test conditions
- Engine is OK mechanically.
- No fault must be stored in DTC memory.
Reading Diagnostic Trouble Codes
Clearing Diagnostic Trouble Codes

Test sequence
- Connect VAG1551 Scan Tool ((VAG1552). Start engine and select "Address word" 01 of engine control module. When doing this the engine must be running at idling speed. [1][2]Reading and Clearing Diagnostic Trouble Codes

Indicated on display:

Rapid data transfer HELP
Select function XX

- Press keys 0 and 8 for the function "Read measuring value block" and confirm entry with Q key.

Indicated on display:

Read measuring value block
Input display group number XXX

- Press keys 0, 1 and 4 for "Display group number 14" and confirm entry with Q key.

Indicated on display: (1 to 4 - Display zones)

Read measuring value block 14 ->
1 2 3 4

- Check total number of misfires in display zone 3:
Specification: 0 to 5

- Check misfire recognition status in display zone 4:
Specification: activated

If the specifications are obtained:
- Press -> key.
- Press keys 0 and 6 for the "End output" function and confirm input with the Q key.
- Switch off ignition.

If the specifications are not attained:
- Change to display group 15 as follows:
- Press key 3 ((VAG1551) or key (Up arrow) ((VAG1552).

Indicated on display: (1 to 4 = Display zones)

Read measuring value block 15 ->
1 2 3 4

- Check the misfiring in display zones 1 to 3.
Specification: 0 to 3

- Check misfire recognition status in display zone 4:
Specification: activated

- Change to display group 16 as follows:
- Press key 3 ((VAG1551) or key (Up arrow) ((VAG1552).

Indicated on display: (1 and 4 Display zones)

Read measuring value block 16 ->
1 4

- Check the misfiring in display zones 1 to 3.
Specification: 0 to 3

- Check misfire recognition status in display zone 4:
Specification: activated
Specification: 0 to 3

- Press -> key.

If the specifications are obtained:
- Press keys 0 and 6 for the "End output" function and confirm input with the Q key.
- Switch off ignition.

If the specifications are not attained:
- Check the spark plugs and ignition/HT cables, Removing and installing parts of the ignition system.
- Check ignition coils with power output stages.
- Check injectors.